Satellite deployer with externally adjustable payload restraint

ABSTRACT

A satellite dispenser and method of using same are disclosed. In various embodiments, a satellite dispenser as disclosed herein includes a dispenser body defining an interior cavity to accommodate a payload; and a plurality of externally adjustable restraints positioned within the interior cavity and configured to be extended further into the interior cavity by actuation of a manual interface external to the interior cavity.

CROSS REFERENCE TO OTHER APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/541,493 entitled SMALL SCALE SATELLITE DEPLOYER filed Aug. 4,2017 which is incorporated herein by reference for all purposes.

GOVERNMENT LICENSE RIGHTS

This invention was made with Government support under Contract No.2014-14031000011 awarded by a United States Government Agency. TheUnited States Government has certain rights in the invention.

BACKGROUND OF THE INVENTION

Small scale satellites, such as CubeSat or other small satellites, maybe launched into space in a launch vehicle that includes a plurality ofsuch satellites, each contained in a “dispenser” device, sometimesreferred to as a small scale satellite “deployer”, configured to deploythe small scale satellite in a controlled manner, e.g., to achieve atarget orbit. The terms “dispenser” and “deployer” are usedinterchangeably in this specification.

Satellites conforming to the CubeSat Design Specification may have asize and form factor of a corresponding type or class of CubeSat asdefined by the standard. The size and form factor of a CubeSat is basedon a standard 10×10×11.35 cm3 unit designed to provide 10×10×10 cm3 (or1 liter) of useful volume. CubeSats of different types may comprise adifferent number of such units. For example, CubeSats comprising 1, 3,6, or 12 units, sometimes designated as 1 U, 3 U, 6 U, and 12 UCubeSats, respectively, may be encountered. Other satellites comprisingother whole or fractional numbers of standard units may be launched anddeployed.

Small scale satellite dispensers typically have a shape, size, and formfactor to accommodate a corresponding small scale satellite, andcommonly have a door that provides access to a payload area of thedispenser. The small scale satellite (payload) is loaded into thedispenser through the opening associated with the door, with the door inthe open position. The door is closed and secured in the closedposition. The dispenser may be arranged with other dispensers in achassis configured to accommodate multiple dispensers. The chassis isloaded into a launch vehicle, such as a rocket, and launched into space.Control circuits initiate deployment of the small scale satellite at atime, orientation, etc. associated with the target orbit of eachrespective small scale satellite. Typically, a satellite is deployed bycausing the dispenser door to open at a precise time, resulting in thesmall scale satellite being ejected from the dispenser and into orbit.Solar panels, antennae, and other appendages and auxiliary equipment mayopen, extend, or otherwise deploy once the small scale satellite hasbeen ejected from the dispenser.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1A is a diagram illustrating an embodiment of a small scalesatellite dispenser.

FIG. 1B is a diagram illustrating an embodiment of the small scalesatellite dispenser 100 of FIG. 1A with the door 104 open.

FIG. 1C is a diagram illustrating an embodiment of the small scalesatellite dispenser 100 of FIG. 1A with the door 104 open and thepayload 106 ejected from the payload area defined by dispenser body 102.

FIG. 2A is a diagram illustrating an embodiment of a small scalesatellite dispenser provided with a pyrotechnic cutter door releasemechanism prior to cutter activation.

FIG. 2B is a diagram illustrating an embodiment of a small scalesatellite dispenser provided with a pyrotechnic cutter door releasemechanism after cutter activation.

FIG. 3A is a diagram illustrating an embodiment of a composite guiderail and a mold to fabricate same.

FIG. 3B is a diagram illustrating an embodiment of a satellite dispenserwith composite guide rails.

FIG. 4A is a diagram illustrating an embodiment of a satellite dispenserpusher plate assembly.

FIG. 4B is a diagram illustrating front and side views of the satellitedispenser pusher plate assembly 400 of FIG. 4A.

FIG. 5 is a diagram illustrating an embodiment of a satellite dispenserwith externally adjustable payload restraint(s).

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

A small scale satellite dispenser with one or more externally adjustablepayload restraints is disclosed. In various embodiments, a payload isheld securely in place inside the dispenser by one or more externallyadjustable spacers, sometimes referred to herein as a “tab” or “foot”,positioned on the inside face of the door and/or the dispenser end plateand extending into the dispenser to an extent and/or applying to thepayload a degree of force that is adjustable by applying a prescribeddegree of torque to a input interface, such as a fastener and/orfastener head, accessible from an outside face of the door. In someembodiments, the prescribed torque may be determined empirically. Forexample, for a given payload, tests may be performed to determine howmuch the payload vibrates inside the dispenser under given conditions.In various embodiments, the feet are low profile to avoid interferingwith satellite deployment.

FIG. 1A is a diagram illustrating an embodiment of a small scalesatellite dispenser. In the example shown, dispenser 100 includes adispenser casing or body 102 with a door 104 at one end. In the stateshown in FIG. 1A, the dispenser door 104 is closed, as it would besubsequent to a small scale satellite being loaded into the dispenser100 but before deployment.

FIG. 1B is a diagram illustrating an embodiment of the small scalesatellite dispenser 100 of FIG. 1A with the door 104 open. A small scalesatellite 106 is visible in the payload area defined by dispenser body102. The state shown in FIG. 1B may be associated with loading thepayload 106 into the dispenser 100, but prior to the door 104 beingclosed, and/or just prior to ejection of payload 106 after the door 104being opened.

FIG. 1C is a diagram illustrating an embodiment of the small scalesatellite dispenser 100 of FIG. 1A with the door 104 open and thepayload 106 ejected from the payload area defined by dispenser body 102.In various embodiments, the payload 106 may have been ejected at leastin part by a spring-loaded pusher plate against which the payload 106had been pressed against during loading of payload 106 into dispenser100, thereby compressing one or more springs associated with the pusherplate.

In various embodiments, the state of dispenser 100 as shown in FIGS. 1Band 1C is attained at least in part by activating a door releasemechanism (not shown in FIGS. 1A through 1C) configured to hold door 104in the closed position prior to activation. Upon activation of the doorrelease mechanism, the door 104 is no longer held in the closedposition. In various embodiments, one or more springs compressed byclosing door 104 and securing door 104 in the closed position may, uponactivation of the door release mechanism, cause the door 104 to bepushed open, as in FIGS. 1B and 1C, allowing the payload 106 to beejected, as shown in FIG. 1C.

FIG. 2A is a diagram illustrating an embodiment of a small scalesatellite dispenser provided with a pyrotechnic cutter door releasemechanism prior to cutter activation. In the example shown, satellitedispenser 200 includes a dispenser body 202 and door 204. The door 204is held closed in the state shown by a door release mechanism 206 whichin this example includes a wire or cable (not shown in FIG. 2A) to holdthe door closed prior to deployment and two pyrotechnic cutterspositioned and configured to cut the wire or cable to release the door204 to enable the door 204 to open. In the example shown, electricalleads 208 are connected to the pyrotechnic cutters included in doorrelease mechanism 206. In various embodiments, signals and/or power toactivate the pyrotechnic cutters is/are provided via leads 208, e.g.,from a driver or similar component comprising and/or otherwiseassociated with the dispenser 200.

FIG. 2B is a diagram illustrating an embodiment of a small scalesatellite dispenser provided with a pyrotechnic cutter door releasemechanism after cutter activation. In the state shown in FIG. 2B, thepyrotechnic cutters comprising door release mechanism 206 have beenfired resulting in the cable or wire holding door 204 closed being cut.In the example shown, the door 204 has been assisted in opening by aspring-loaded pusher 210 being pushed out from the door releasemechanism 206 once the wire or cable holding the door 204 shut had beencut. Also shown in FIG. 2B is a recess or cavity 212 into which a doorside portion of the wire or cable that had been holding the door 204closed has been pulled, e.g., by a spring-loaded plunger configured toextend into the cavity 212 pulling the door end of the cut wire or cableinto cavity 212. In various embodiments, the wire or cable retractionmechanism configured to pull the free end of the cut wire or cable intocavity 212 ensures the loose (door) end of the cut wire or cable doesnot interfere with ejection and/or deployment of the small scalesatellite from dispenser 200.

FIG. 3A is a diagram illustrating an embodiment of a composite guiderail and a mold to fabricate same. In the example shown, layers 302 ofcarbon (or other) fiber reinforced fabric that has been pre-impregnatedwith a resin system, such as epoxy, are laid up on a mold 304. Mold 304may be made of machined aluminum or another durable material withpredictable thermal expansion behaviors for the elevated temperature atwhich the composite guide rail is cured.

In various embodiments, to form a composite guide rail as disclosedherein, the mold 304 is polished, laminate layers 302 are laid on top,the layers 302 are topped with a peel-ply perforated release film andbreather material, and the assembly 302, 304 is placed in a vacuum bag.Once the mold 304 and laminate 302 are sealed in the vacuum bag, the bagis purged of all gasses with a vacuum pump. The assembly 302, 304 iscured in a high pressure, high temperature autoclave for the specifiedtime required by the pre-preg laminates 302.

In various embodiments, composite guide rails as disclosed herein may becarbon composite rails with a layer of silicon carbide on the payloaddispenser interface. The silicon carbide provides a very hard and smoothsurface for the CubeSat rails to interface with. In some embodiments, asilicon carbide layer is laid right on top of the carbon fiber laminatelayers (e.g., layers 302 in FIG. 3A) during the fabrication process.

FIG. 3B is a diagram illustrating an embodiment of a satellite dispenserwith composite guide rails. In the example shown in FIG. 3B, a finishedcomposite guide rail is shown in positions at the four corners of thesatellite dispenser payload chamber (of the dispenser body, not shown inFIG. 3B. In various embodiments, the four corners of the payload 320,e.g., CubeSat rails or other small scale satellite corner/edgestructures, engage and ride on the inner guide defined by the centrallobe of the guide rail 302. In various embodiments, the silicon carbidelayer on the side of guide rails 302 that face and engage the payload320 enables the payload 320 to slide more freely along the guide rails302, e.g., during satellite ejection and deployment.

FIG. 4A is a diagram illustrating an embodiment of a satellite dispenserpusher plate assembly. In the example shown, pusher plate assembly 400includes a pusher plate 402 coupled to a dispenser end plate or panel404 by a spring 406. In various embodiments, a satellite loaded into adispenser that includes pusher plate assembly 400 is pressed against thepusher plate 402, comprising spring 406, enabling the dispenser door tobe closed. Upon release of the dispenser door to eject and deploy thesatellite, the spring 406 extends and pushes pusher plate 402 in thedirection of the dispenser door opening, which in turn pushes thesatellite, riding on one or more guide rails, such as guide rails 302 ofFIGS. 3A and 3B, out and through the dispenser door opening.

FIG. 4B is a diagram illustrating front and side views of the satellitedispenser pusher plate assembly 400 of FIG. 4A. As shown in FIG. 4B, thepusher plate 402 includes protrusions 410, 412, 414, and 416 atlocations on pusher plate 402, each of which aligns, in variousembodiments, with a corresponding groove comprising a guide rail (e.g.,guide rail 302) positioned in an interior corner of a dispenser payloadarea.

In the example shown, protrusions 410, 412, 414, and 416 are formed asan integral part of the pusher plate 402 and extend back towards the endplate as tapered posts, the distal ends of which engage, when thedispenser is loaded and spring 406 is compressed, with correspondingnylon (or other polymer0 adjustable “feet”, represented in FIG. 4B byfeet 420 and 422. Each of the tapered posts comprising the fourprotrusions (410, 412, 414, 416) aligns opposite a corresponding one ofthe feet. Each of the feet (e.g., 420, 422) is adjustable in its extentinto the payload area of the dispenser and/or the force applied to thepusher plate 402 via the protrusion 410, 412, 414, and 416 with which itis aligned by an adjustment screw (or similar structure), represented inFIG. 4B by adjustment screws 424 and 426. In various embodiments, thenylon (or other) feet 422, 424 and associated adjustment screws 424, 426are torqued to a prescribed torque to secure the payload firmly in thepayload area, e.g., to avoid movement during flight, which could damagethe satellite.

FIG. 5 is a diagram illustrating an embodiment of a satellite dispenserwith externally adjustable payload restraint(s). In the example shown,the satellite dispenser 500 includes an interior payload area defined byfour longitudinal side walls 502, end plate or panel 404, and door 506.As shown, a small scale satellite payload 504 is positioned in thedispenser 500. Door 506 is hinged at the bottom edge, as shown, at hinge508 and is held closed in the state shown by door release mechanism 510.In the example shown, the payload 504 is held securely in place byadjustment of feet on the four protrusions of the pusher plate 402,represented in FIG. 5 by feet 420 and 422, and four feet at each cornerof the inner face of door 506, represented in FIG. 5 by feet 512 and516. In various embodiments, the respective external adjustment screws(or other external adjustment interfaces), represented in FIG. 5 byadjustment screws 424, 426, 514, and 518, are torqued, each to aprescribed torque, to ensure the payload 504 is held securely in place.

In various embodiments, at least the dispenser door feet, such as feet512, 516, are shaped to have a low profile, e.g., not to extend too farbeyond the inner face of the door 506, to minimize the risk ofinterference with ejection of the payload 504 once the door 506 isreleased and springs open.

In various embodiments, the degree of torque applied to the externaladjustment screws (e.g., screws 424, 426, 514, and 518) is determinedempirically, for example for a given payload and/or class or type ofpayload. For example, vibration sensors may be used to determine foreach torque in a range of values and for a given stimulus applied to thedispenser 500 a corresponding amount of vibration that is imparted tothe payload 504. An amount of torque determined to ensure vibrationbelow a prescribed or design level is applied.

In various embodiments, structures and techniques disclosed hereinensures a payload is positioned securely within a dispenser, reducingthe risk of damage to the payload due to excessive vibration duringflight.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A satellite dispenser, comprising: a dispenser body defining an interior cavity to accommodate a payload; a plurality of externally adjustable restraints positioned within the interior cavity and configured to be extended further into the interior cavity by actuation of a manual interface external to the interior cavity; an end plate at a first end of the interior cavity, wherein at least a subset of the restraints are positioned on or in the end plate; and a pusher plate assembly positioned adjacent to the end plate, wherein the pusher plate assembly comprises a pusher plate having a plurality of posts and each of at least a subset of the posts is aligned with a corresponding one of the restraints positioned on or in the end plate.
 2. The satellite dispenser of claim 1, wherein the manual interface is accessible when a payload has been loaded into the interior cavity through a dispenser door opening of the dispenser and a dispenser door of the dispenser has been closed.
 3. The satellite dispenser of claim 1, wherein the respective externally accessible manual interfaces of the restraints positioned on or in the end plate extend through the end plate.
 4. The satellite dispenser of claim 3, wherein the respective externally accessible manual interfaces of the restraints positioned on or in the end plate comprise adjustment screws.
 5. The satellite dispenser of claim 1, wherein at least a subset of the restraints are positioned on or in a dispenser door of the dispenser.
 6. The satellite dispenser of claim 5, wherein the respective externally accessible manual interfaces of the restraints positioned on or in the dispenser door extend through the dispenser door.
 7. The satellite dispenser of claim 5, wherein the respective externally accessible manual interfaces of the restraints positioned on or in the dispenser door comprise adjustment screws.
 8. The satellite dispenser of claim 1, wherein the restraints comprise nylon or another polymer.
 9. The satellite dispenser of claim 1, wherein the restraints have a low profile to avoid interfering with ejection of a payload from the dispenser.
 10. A method of loading a satellite dispenser, comprising: inserting a satellite into the satellite dispenser, wherein the satellite dispenser comprises: a dispenser body defining an interior cavity to accommodate the satellite; a plurality of externally adjustable restraints positioned within the interior cavity; an end plate at a first end of the interior cavity, wherein at least a subset of the restraints are positioned on or in the end plate; and a pusher plate assembly positioned adjacent to the end plate, wherein the pusher plate assembly comprises a pusher plate having a plurality of posts and each of at least a subset of the posts is aligned with a corresponding one of the restraints positioned on or in the end plate; closing a dispenser door of the satellite dispenser to seal the satellite inside the satellite dispenser; and adjusting a plurality of externally adjustable manual interfaces, wherein each of the manual interfaces is associated with a corresponding one of the plurality of restraints, each of the manual interfaces is adjusted to corresponding a prescribed torque, and at least a subset of the plurality of restraints are correspondingly adjusted to a position at which the subset of the plurality of restraints secure the satellite.
 11. The method of claim 10, wherein the prescribed torque is determined at least in part by iteratively applying varying amounts of torque, and for each torque applied performing a test to determine a measure of how securely the satellite is held in place.
 12. The method of claim 11, wherein the test comprises a vibration test.
 13. The method of claim 10, wherein the externally adjustable manual interfaces comprise screws or other fasteners.
 14. The method of claim 10, wherein the plurality of restraints comprise nylon or other polymer feet.
 15. The method of claim 10, wherein the plurality of externally adjustable manual interfaces and associated interior payload restraints are distributed at opposite ends of the satellite dispenser.
 16. The method of claim 15, wherein the plurality of externally adjustable manual interfaces and associated interior payload restraints includes two or more externally adjustable manual interfaces and associated interior payload restraints at each of the opposite ends of the satellite dispenser. 